Tool grinding assembly



p 1944- ?r. J. NOVOTNY.

TOOL GRINDING ASSEMBLY Filed July 19, 1941 Patented Sept. 12, 1944 TOOL GRINDING ASSEMBLY 7 Thomas John Novotny, Le Sueur, Minn., assignor Minnesota. Valley Canning Company,

Le Sueur, a corporation of Minnesota 7 Application July 19, 1941, Serial No. 403,211

6 Claims. (Cl. 51-223) This invention relates to a tool grinding assembly, and more specifically to a carriage for holding an instrument and bringing it into contact with a sharpening device.

One of the objects of this invention is to provide a tool grinding assembly comprising a tool sharpening device and a carriage which is mounted in such a manner that it is capable of moving the tool transversely with respect to, and bringing it into contact with, a working face of the sharpening device.

Another object of this invention is to provide a carriage of the type described that is designed to hang in a vertical plane which is slightly removed from the working face of the sharpening device.

Still another object of this invention is to provide a carriage of the type described which is pivotally and slidably mounted by one extremity at a point above the sharpening device and the lower extremity of which lies substantially opposite the working face of the sharpening device.

A further object of this invention is to provide a carriage of the type described provided with means vby which the tool may be securely held in position at the desired angle with respect to the sharpening device during the sharpening operation.

With these and other objects in view, this in vention embraces the concept of providing a tool sharpening assembly comprising a sharpening device and a work carriage, the latter being slidably and pivotally mounted at points above the sharpening device and provided with means to secure and support the tool which is to be sharpened. The carriage is suspended so that it hangs in a vertical plane which is slightly offset horizontally from the working face of the sharpening device in order that the tool will normally be out of contact with the sharpening device. The pivoting arrangement permits the tool to be swung against the sharpening device.

This construction and position of the carriage provides an eflicient means whereby the tool to be sharpened can be brought into contact with the sharpening device by the operatorand also provides means for readily moving the work piece transversely across a working face of the device to obtain the desired cutting edge without it becoming necessary for the operator to support the work piece during thesharpening operation. I

closed in Figure '1, showing in broken line the carriage in advanced or operative position.

Figure 3 is a detailed view in perspective of the tool sharpening assembly, disclosing the work piece in contact with a face of the sharpening device.

Figure '4 is an enlarged view in side elevat'ion of the tool carrying portion of the assembly, showing in broken line the tool' carrying mem ber in advanced position.

Figure 5 is a view taken along line 5-5 of Fig ure 1, looking in the direction of the arrows.

Figure 6 is a view taken along line 6-6 of Figure 1, looking in the direction of the arrows. As shown in the drawing, the tool sharpening assembly comprises a" tool sharpening device A and a work carriage B. The type of tool sharpening device A will vary 'in accordance with the type of work piece which is to be sharpened, butfor purposes of present illustration, it is shown as comprising a stand I which supports a base 2 upon which is mounted a rotatable wheel 3 of double conical shape. The wheel 3 is an emery or grinding stone of suitable characteristics, and is driven by any suitable means, such as a belt 4-.

The work carriage B is suspended from a channel shaped hanger I, the extremities of which are flanged to form a track 8. Mounted in the track 8 are a plurality of carriages 9, each of which is provided with two pairs of rollers I0 which are journalled on axles H.

Each carriage 9 is provided with a pair of tie bands 12 from which is pivotally suspended a' T-shaped member l3 by means of a nut and bolt arrangement M. The flanged lower extremity of each T-shaped member I3 is bolted, or attached in any other suitable manner, to the flanged extremity l5 of a rocker arm I6. v

The rocker arms I6 are bound together and braced by a pair of cross arms V l! which extend the length of the carriage. These cross arms ll pass through sleeves l8 in which they are secured by bolts l9. As best shown in .Figure 6, each sleeve I8 is provided with a collar 20 by means of which it is attached to its respective rocker arm l6. 7

"Attached to the lower end of each of the rocker arms 5 by brazing or other suitable means is a semi-circular portion 2| in the shape of a gooseneck or other suitable design. Each of the portions 2| is provided with a sleeve 2| through which passes a handle 22. This rod 22 serves as an additional brace as well as a handle to be graspedby the operator. A. set screw 23 is threaded in the sleeve 2| and holds the handle 22 in fixed position within the sleeve.

Attached at right angles to the free end of the portion 21 is a sleeve 25 in which is rotatably f mounted an elbow 26. The elbow 26 may be fixed .in the sleeve 25 at the desired angle by means of'a set screw 21, and its end is provided with a jaw clamp 28 provided with a thumb screw 29.

In order to aifordadditional support, .double clamps may be substituted for each of the single jaw clamps 28. The work piece or tool to be sharpened, which is shown in the present instance as a mower blade, is inserted within the jaw' clamps 28 and securely held therein by means of thumb screw 29.

is also provided which comprises a screw threaded handle 3| on which is mounted a lock nut 32 and a jaw clamp 33, in which latter there is provided a threaded aperture to receive the threaded end of the handle. afiixed to the blade, and may also be changed from time to time, by extending the jaws 33 about the lower end of the blade, and then screwing the. handle 3| until its end bears against the blade and'holds the same in a firm grip. For any extended operation, the lock nut 32 may be tightened upon the threaded end of handle 3| to prevent rotation and loosening of the latter;

In operation, the selected work piece 34 is placed in the jaw clamps 2B, pivotally mounted onthe members 2|, and locked therein by means of thumb screws 29. -It will be appreciated, of course, that the blade .must be so positioned in the jaw'clamps 28 that 'the'original sharpened face of the blade is'opposite the wheel 3, so .that' during the sharpening operation the ground face will be exposed to the wheel. The angular ad:

justment orthe blade with respect to the sharp- In this way, the

The hand clamp 30 may be hand clamp may be readily disengaged and re- .clamped as the sharpening progresses.

After the two opposed faces of the particular section are sharpened, the rocker arm i 6 is swung away from the wheel and the carriage B moved along the track so that the succeeding edges are in proper position for engaging the wheel 3. The rocker arms l6 are then ,moved to .throw the blade into contact with such new edges for sharpening, and this operation is repeated until all of the sections or teeth have been properly sharpened.

It willbe appreciated from the foregoing that this invention constitutes a device which facilitates the sharpening of various instruments, particularly relatively long instruments, such as mower blades. By the use of such a device, only i one man is required for the sharpening of blades,

ening wheel is secured by-rotating the elbow 2B withinsleeve 25, and when such proper angularity is obtained the lock nut 21 is tightened to hold the blade in such position.

The wheel 3 is then started, and the carriage. B is moved along the track 8,until the blade be appreciated that the rocker arms are pivoted so that the blade clears the wheel.

When the carriage is so positioned that the desired cutting edge of the particular tooth or section is opposite the wheel, the handle arm 22 is then moved toward the wheel until the cutting edge or edges contacts the wheel. It will be appreciated that, except for the extreme cutting edges of the end sections, the oppo'sededges of two adjacentv sections will be sharpened at thesame time by virtue of the double conical shape of the wheelQas best shown in'Figure 3;

In order to afford additional support for the blade,'particularly when sections remote from the clamps 28 'are being sharpened. the hand clamp 30 is aifixed to the blade near the sections that are being sharpened, and, of course, this ferred embodiment ofmy invention, I wish it to be understood that I do not confine myself to: the precise details .of construction herein' set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the'appended claims.

I claim:

1.'A device for sharpening tools comprising a' work carriage assembly and a sharpening device, said work carriage assembly comprisinga track mounted above the sharpening device, a plurality of devices slidably mounted on said track, a rocker arm pivotally suspended from each slidably mounted device, a plurality of cross arms connecting said rocker arms to form a carriage, said carriage being suspended from the track in'a vertical plane, said vertical plane being slightly offset with respect to the sharpening device, an offset portion attached to the lower extremity of each rocker arm, a handle joining the offset portions, and a device pivotally mounted on each offset portion, each of said devices being'provided with clamping means to secure the tool to be sharpened to the said carriage and said clamping devices being disposed horizontally opposite the said working device.

2. A device for sharpening tools comprising a work carriage assembly and a sharpening device,

said work carriage assembly comprising a track 7 mounted above the sharpening device, a plurality of devices slidably mounted on said track, a

rocker arm pivotally suspended from each slidably mounted device, a plurality of cross arms connecting said rocker arms to form a carriage, said carriage being suspended from-the track in a vertical plane, said, vertical plane being slightly ofiset'with respect to the sharpening'device and said cross arms being slidably connected to said rocker arms thereby permitting the distance between the rocker arms to be varied, an oifset porvices being provided with clamping means to secure the tool to be sharpened to the said carriage and said clamping devices being disposed horizontally opposite the said working device.

3. In a construction for sharpening blades or the like having a sharpening member and a work carriage assembly that is pivotally and slidably mounted with respect to the sharpening member, the carriage assembly including a track mounted above the sharpening member, a plurality of vertically disposed rocker arms mounted for longitudinal sliding movement on said track, longitudinally extending elements cooperating with said rocker arms to maintain the arms in spaced relation, further means to permit each rocker arm to be adjusted either closer to or farther away from the other arms to accommodate blades of varying length, a blade supporting device pivotally attached to the free end of each rocker arm and located at a point adjacent to but spaced from the sharpening member, and means to secure the blade in said supporting device.

4. A device for sharpening blades and the like comprising a sharpening member, a carriage mounted for swinging movement toward and away from the sharpening member, blade supporting means carried by the free end of the carriage and angularly adjustable with respect thereto, and means on the carriage to fix the blade supporting means in angular adjusted position in relation to the carriage whereby the blade engages the sharpening member at a fixed angle when the carriage is swung toward said sharpening mmeber.

5. A device for supporting and moving an elongated blade relative to a rotatable grinding wheel for sharpening said blade comprising a support, a plurality of arms mounted on the support and capable of lateral and longitudinal movement with respect to the axis of rotation of the grinding wheel, means adjustably carried by each of said arms for supporting the blade, rigid means extending between the arms, and means for securing the arms in adjusted position with respect to said rigid means thereby to accommodate blades of varying lengths.

6. A device for supporting and moving an elongated blade relative to a rotatable grinding wheel for sharpening said blade comprising a support, a plurality of arms mounted on the support and capable of lateral and longitudinal movement with respect to the axis of rotation of the grinding wheel, means adjustably carried by each of said arms for supporting the blade, rigid means extending between the arms, and means for securing the arms in adjusted position with respect to said rigid means thereby to accommodate blades of varying lengths, and a hand engaging member adjustably secured to the blade and serving to efiect movement of the blade and sup porting device.

THOMAS JOHN NOVOTNY. 

